我想选择一级目录和相应的二级目录，想下面的代码，但一直实现不了，选择了一级目录，二级目录没有反映啊，各位帮帮忙吧，该怎么办，谢谢～～～～！
<tr>
                      <td width="16%" height="25">选择分类：</td>
                      <td width="84%" height="25">
                
<%
connstr="DBQ="+server.mappath("database/database.mdb")+";DefaultDir=;DRIVER={Microsoft Access Driver (*.mdb)};"
     set conn=server.createobject("ADODB.CONNECTION")
     conn.open connstr                 
        set rsb=server.createobject("adodb.recordset")
        sqlb = "select * from gqlb "
        rsb.open sqlb,conn,1,1
        if rsb.eof and rsb.bof then
            response.write "请先添加栏目。"
        else
        %>
                    <select name="lbid" onChange="changelocation(document.myform.lbmc.options[document.myform.lbmc.selectedIndex].value)" size="1">
                      <option selected value="<%=trim(rsb("lbid"))%>"><%=trim(rsb("lbmc"))%></option>
                      <%
            dim selclass
            selclass=cstr(rsb("lbid"))
            rsb.movenext
            do while not rsb.eof
            %>
                      <option value="<%=trim(rsb("lbid"))%>"><%=trim(rsb("lbmc"))%></option>
                      <%
                rsb.movenext
            loop
        end if
        rsb.close
            %>
                    </select>
                    <select name="lbid1">
                      <option value="" selected>不指定小类</option>
                      <%
           connstr="DBQ="+server.mappath("database/database.mdb")+";DefaultDir=;DRIVER={Microsoft Access Driver (*.mdb)};"
     set conn=server.createobject("ADODB.CONNECTION")
     conn.open connstr         
           set rsss=server.createobject("adodb.recordset")
            sqlss="select * from gqlb1 where gqlb="&selclass&""
            rsss.open sqlss,conn,1,1
            if not(rsss.eof and rsss.bof) then
            %>
                      <option value="<%=rsss("id")%>"><%=rsss("gqlb1")%></option>
                      <% rsss.movenext
                do while not rsss.eof%>
                      <option value="<%=rsss("id")%>"><%=rsss("gqlb1")%></option>
                      <%
                    rsss.movenext
                loop
            end if
            rsss.close
            %>
                    </select></td>                            
                    </tr>